Application Configuration Access Protocol Praveen S Thangavelu Nov Advisor: Dr Chung-E-Wang Department of Computer Science, CSUS

Motivation and Agenda  Opportunity to study, design and implement a real life internet protocol  Solution to client mobility  Understanding RFC specifications  Agenda Overview Protocol Framework ACAP Commands Design Issues – Methodology, scope & clients Major functionality Problems Results and Future enhancements

Overview  Companion protocol to IMAP  IMAP vs. ACAP  History – IMSP and ACAP  Directory Service??  Application of ACAP and Example  ACAP Usage for Mobile User  Example Clients EUDORA – ACAP enabled

Data Model and Design Goals  ACAP Data Model Datasets, entries and attributes Tree of entries Rules with which clients access datasets are specified in dataset classes Pre-defined attributes  Design Goals Access Configuration/Preferences remotely Emphasis on client simplicity Easily manageable – Dataset Inheritance Clients with intermittent access- slow clients – modtime attribute Operated well with Large clients

Protocol Framework  Link Level Assumes reliable data stream (TCP/Port 674)  Client Server connection Text based line oriented protocol  Commands and responses Client command Server data Server completion results  Tagged response; command continuation request  Operational Considerations Data transferred comply with underlying transport window size Multiple commands

Server States  Connection ACAP greeting  Rejected Connection Bye Greeting  Successful Authenticate  Logout Logout command Server shutdown Connection closed Init Connection/Server greeting Non-authenticated Authenticated Logout and close connection

Protocol Elements  Datasets Entries, attributes  Response code OK, BAD, NO  Access Control Lists  Namespaces  Functionality Communication Dataset definition Parsing system

Implementation Issues  Communication Subsystem  Multiple clients  In memory representation of data  ACAP Command Parsing  Some Server Response codes – Modified  Datasets CREATE, READ, STORE  Compatibility with real time mail clients Other mail clients – pine

Some Sample Results  Client:  Server: * ACAP (IMPLEMENTATION "Plugged In ACAP Server v1.03") (CONTEXTLIMIT "150") (SASL "CRAM-MD5" "KERBEROS_V4")  Client: GH45 STORE ("/addressbook/user/praveen"  "Contact.Name" "Praveen" "Contact. "   Server: GH45 OK "STORE completed"  Client: GH46 LOGOUT  Server: * BYE "See ya later"  Server: GH46 OK "LOGOUT completed“  Planning to store configuration Information for Pine or ELM

Future Enhancements  Server Replication/ Mirroring  Extending per user data to group of users  Scope Extension Complex Search Queries Authorization using ACL Include contexts per session  Extension to Web based clients like squirrel mail